By: Paul W. Barada, Monster Salary and Negotiation Expert

A simple background check to ensure a candidate didn't lie on his resume or job application isn't enough. It’s just the first step. The second, and more important step, is ensuring that the candidate can do what he claims to be able to do. In other words, careful job performance-based reference checking is more important than ever in the employee selection process.

So what are some of the best questions to ask? Once the reference is actually on the phone, the first question to ask is, "How are you acquainted with the candidate?" The answer to this question will accomplish several things. First, it will confirm when, where and whether or not the reference and the candidate have ever worked together, and what the nature of their association was. Did the reference work for the candidate or the other way around, or were they coworkers? Did they work together on a daily basis or just once in a while? The answer to this critical question will allow the reference checker to determine how much weight to give the responses to subsequent questions.

The next question that should be asked is, "How long did you and the candidate work together?" Once again, the length of the association will help establish the credibility of responses to other questions. Obviously, if the reference worked with the candidate for several years, the responses will carry more weight than if the length of their association was only a few months or less.

Next, it’s important to ask the reference to describe the candidate's day-to-day responsibilities on the job. This is the point at which the reference checker should be comparing what the candidate’s resume says with what the references have to say. The completeness of the answer will also reveal still more about how well the reference really knew the candidate. An evasive or vague answer may suggest, for instance, that the candidate overstated his or her claim to have worked with the reference every day for several months. A red flag should go up if the reference can't describe what the candidate's job responsibilities were with some degree of thoroughness.

Another of the essential questions that must be asked of every reference is, "What do you think the candidate needs to really continue his or her career development and professional growth?" The response to this question can provide invaluable insight into the candidate's suitability for the job to be filled.

Toward the end of the interview, there are other important questions that always should be asked, such as, "Why did the candidate leave?” and "Could the candidate have stayed if he had wanted to?" If the candidate is still working at the same place as the reference, the question becomes, "Why is the candidate contemplating a job change?" Finally, every reference should be asked, "If you were hiring people, would you hire the candidate and, if so, for what type of position?"

While this is not intended to be an exhaustive list of questions reference checkers should ask, it’s a starting point that allows you to establish a reference’s credibility.